Leprosy how does it attack and spread

Leprosy usually begins as an indeterminate form that can heal spontaneously, remain unchanged for long periods, or progress to a more severe form.

This initial indefinite form can produce patches or macules of the skin, which is not clear with little hypopigmentation. In parallel, such patches may coincide with hypoesthesia of the corresponding skin nerve. If the disease develops, tuberculoid leprosy can develop as long as the host immune response is preserved enough.

At this stage, rapid skin sensation loss due to severe neurological damage can occur, as well as local paralysis, loss of sweat and sebaceous glands, and hair loss.

The skin shows macular lesions with significant hypopigmentation; peripheral nerves are infiltrated and may present as thick subcutaneous bundles. Secondary symptoms include bruised skin under hypoesthesia due to local external damage and superinfection with poor healing ulcers [ 21 ]. The lepromatous stage occurs in individuals with poor immune reactions. Clinically, this is the most severe form and can lead to mutilation.

Skin lesions may appear as macules, papules, or plaques with hypopigmentation. The most affected areas are the ears, the central face, the fingers, and toes, but the distal extremities, such as the extensor surfaces of the thighs and forearms, can also be affected. Often, blindness can occur when the eye is exposed.

Osseous resorption of the nostrils and destruction of the bridge of the nose result in severe facial mutilation. The Mycobacterium leprae affected throat can cause a distinctive hoarseness. In fact, all other body areas can also be affected, leading to varying clinical features. The fourth stage, called the borderline stage, also exists, which is somewhat intermediate between tuberculoid and lepromatous stages in clinical symptoms. Considering the various clinical symptoms, especially the early stages and stages of minor illness, leprosy can easily be confused with various other diseases.

In contrast, typical skeletal mutilation in the form of severe leprosy leaves a distinctive footprint of disease that may be identified in historic relics with high levels of certainty [ 21 ]. More advanced leprosy presentations have been reported and classified as tuberculoid leprosy and lepromatous leprosy. Many other clinical presentations, known as intermediate or borderline leprosy, have been identified and classified among the two types.

But according WHO classification, leprosy is divided into two major groups: pauci-bacillary subtype and multi-bacillary subtype. The WHO system is based on the quantity of skin lesions and the number of bacilli on skin smear.

Skin smears are made by squeezing a fold of skin and making a shallow slit in the skin with a scalpel [ 23 ]. The Ridley-Jopling classification system is based on the histopathology of skin lesions and essentially represents a spectrum of disease. The spectrum of leprosy classification is not static.

For example, in some cases, untreated TT can progress into LL, given a long enough time and the proper immunologic environment. There are the two classification systems that are mutually exclusive. This was confirmed by the WHO Expert Committee on Leprosy at the seventh meeting in , which defined a case of leprosy as follows: A case of leprosy is someone who has one or more of the following features and who still needs to complete a complete treatment: skin lesions hypopigmentation or redness with a definite loss of sensation, peripheral nerve involvement, as shown by neural thickening accompanied by loss of sensation, as well as positive skin-smears for acid-fast bacilli [ 24 ].

The referral of a suspect who has no anesthetic symptoms is given to a person with a higher experience who has been taught peripheral nerves should be straightforward. Skin smear on new case samples can provide quality control. Research into laboratory tests e. Leprosy patients have been traditionally classified based on the number and type of skin lesions into various clinical groups. However, according to current WHO guidelines, only the number of skin lesions determines the length of therapy patients received for leprosy.

Various studies have reported and highlighted the differences between clinical and skin classification and nerve biopsy findings of leprosy patients [ 26 ]. The patients are categorized into PB and MB leprosy depending upon whether the slit skin smears demonstrate any bacilli or not. Earlier, the cases with a bacterial index of 2 or less had been categorized as PB, but later on, for feasibility and operational difficulties, all the patients with demonstrable bacilli in slit skin smear without any reference to bacterial index were to be categorized as MB, whereas WHO Classification for leprosy control program was based on the total number of leprosy lesions in the patient.

This is a corollary to the fact that PB patients have good immunity and present with only limited number of lesions. Furthermore, the single lesions leprosy was also segregated on the ground that this can be treated with the limited amount of chemotherapy. Pauci-bacillary leprosy is found in people with good CMI. The disease remains localized to produce single or little skin lesions with or without peripheral nerve involvement.

The skin lesion may be macular flat or papule slightly raised and plaque. People with strong immune responses are capable of destroying large amounts of normal organisms and skin normally most of them exhibit negative skin examinations.

Multi-bacillary leprosy is found in people with poor CMI. Bacilli multiply and spread more widely resulting in a common disease: usually accompanied by widespread lesions in the skin, nerves, and at lower levels in other organs such as the eyes, respiratory mucosa, testes, and reticuloendothelial system in men and usually the central nervous system and the upper reproductive system in women. The skin lesions may be multiple borderline or uncountable lepromatous.

Lepromatous lesions may be symmetrical and unclear bilateral macules or diffuse infiltration, which may develop into plaque and nodule formation. In addition, there may be nasal bleeding and edema on both legs. If the patient does not receive treatment, the pauci-bacillary form of leprosy can be downgraded to the multi-bacillary form from tuberculoid to lepromatous through the borderline spectrum.

A major problem in the management of leprosy patients is the occurrence of the leprosy reactions, which are consequences of the dynamic nature of the immune response to leprosy bacteria M. Reactions in leprosy constitute the main complications of the disease, which can lead to serious consequences like nerve damage and deformities. Reaction may occur in any type of leprosy expect the indeterminate type.

Unless promptly and adequately treated, it can result in deformity and disability. Three types of reactions recognized are classified as: 1 type 1 reaction T1R , 2 type 2 reaction T2R or erythema nodosum leprosum ENL , and 3 the Lucio phenomenon [ 28 ].

The LR immune-pathogenesis is currently an important research focus, as it can provide relevant targets and goals for early detection and control of this episode [ 29 ]. If there is increase in the immunity, the shift is from borderline spectrum toward the tuberculoid pole and is called upgrading or reversal reaction. On the other hand, if there is sudden shift toward the lepromatous pole with reduction of immunity, it is called as downgrading reaction.

These acute inflammatory events may accentuate the chronic course of the disease in the total clinical spectrum of the disease, usually in Borderline leprosy BT, BB, and BL and rare in LL. Clinical symptoms may present with complain of burning, stinging sensations in the skin lesions.

Type 2 reaction is an immune complex syndrome antigen—antibody reaction involvement complement. T2R occurs mostly in lepromatous LL and sometimes in borderline lepromatous leprosy LL , which occurs mostly during the course of antileprosy treatment. A few cases present for the first time with features of reactions before leprosy is diagnosed and treatment started. In one third of the cases, pain and swelling in the joints precede or are a component of other constitutional symptoms.

In cutaneous onset, there may be appearance of skin lesions in the form of maculopapular, popular, nodular, or plaque type lesions before appearance of constitutional signs and symptoms. Fever, joint pain and constitutional sign and symptom, and skin lesion appear together. T2R without ENL is possible that the manifestations of the reactions may not be confined to the skin, and the patients may develop neuritis or systemic involvement or both, depending upon the target organs where immune complexes deposition occurs [ 28 ].

Lucio phenomenon is a special type of reactions observed in uniformly diffuse shinny infiltrative nonnodular form of LL, which is chiefly encountered in Mexicans. Its unique feature is that it is seen only in untreated cases. The etio-pathogenesis is less well understood. There is marked vasculitis and thrombosis of the superficial and deep vessel, resulting in hemorrhage and infarctions of the skin.

Clinical manifestations begin with slightly indurated red-bluish plaques on the skin with an erythematous halo, sometimes larger inflamed bullous lesions, which burst leaving a deep ulcer with jagged edges. The lesion takes about 3 weeks to develop an ulcer from the initial lesion, and it heals slowly and secondary cellulitis may complicate. Patients remain afebrile [ 28 ]. The disease can affect the nerves responsible for blinking, causing the eyes to become very dry and prone to infection.

Ulceration and vision loss can result. Testing a skin or nerve sample in a laboratory can confirm the diagnosis. To treat the disease, the doctor prescribes a combination of two or three antibiotics. A person needs this treatment for 1—2 years. Combining several antibiotics helps reduce the risk of developing antibiotic resistance, according to the CDC.

Antibiotics can kill the bacteria causing the symptoms, stopping the disease. However, it cannot reverse existing damage.

It is essential to contact a doctor as soon as possible if the symptoms start to appear. In the U. In , however, scientists identified another type, Mycobacterium lepromatosis , in Mexico. These bacteria produce slightly different symptoms. So far, there has been very little research into this type. The bacteria spread slowly through the body. As they do so, they attack macrophages , which are cells that represent a key part of the immune system and support the nervous system.

This can lead to a thickening of the nerves under the skin. The authors of a review reached no definite conclusion regarding how the bacteria transmit. The studies they analyzed suggested that the transmission might involve contact with animals, skin-to-skin contact, or droplets from a cough or sneeze. A person would need to be in close contact with someone who has the disease, but is not receiving treatment, for several months in order to contract it. Some armadillos may carry the bacteria.

Anyone who has regular contact with armadillos should speak with their doctor about appropriate precautions. Once a person starts treatment, the bacteria cannot pass on to others. Once treatment is started, the person is no longer contagious.

However, it is very important to finish the entire course of treatment as directed by the doctor. Each year, about people in the United States and , around the world External get the illness. Still, a lot of stigma and prejudice remains about the disease, and those suffering from it are isolated and discriminated against in many places where the disease is seen.

Continued commitment to fighting the stigma through education and improving access to treatment will lead to a world free of this completely treatable disease. Hansen's Disease Leprosy.

Section Navigation.